Background: The present study and for the first time hypothesizes that the patients with left bundle branch block (LBBB) suffer considerably from metabolic syndrome (MetS) and this metabolic phenomenon can be associated with cardiac dysfunction status such as ventricular dilation and reduced left ventricular ejection fraction (LVEF) in these patients.
Methods: A retrospective study was conducted on 220 consecutive patients with diagnosed LBBB. MetS status was diagnosed using the Adult Treatment Panel III of the National Cholesterol Education Program criteria. Systolic function state was assessed using two-dimensional echocardiography.
Results: The overall prevalence of MetS among studied LBBB patients was 16.8%. Regarding left ventricular functional status in the two groups, the mean LVEF in the groups with and without MetS was 37.03 ± 9.09% and 43.43 ± 15.62% with a significant difference (p = 0.017). However, left ventricular dilation was similarly detected in both groups with and without MetS (21.6% versus 30.6%, p = 0.273). Multivariable linear regression model showed subjects with MetS had lower LVEF in the presence of confounders (Beta = 6.915, p = 0.039).
Conclusion: A notable number of LBBB patients suffered from MetS and this metabolic phenomenon is significantly associated with lowering left ventricular function in LBBB patients.